Indications of spin polarized transport in Ba${}_2$FeMoO${}_6$ thin films

Abstract

We have investigated the magnetic and magnetotransport properties of Ba${}_2$FeMoO${}_6$ thin films produced by pulsed laser deposition from optimized bulk material. The films are comprised of grains of crystalline Ba${}_2$FeMoO${}_6$ with a disordered grain boundary region that lowers the net saturation magnetization of the film and prevents full magnetic alignment below a Curie temperature $T_C$$\sim$305 K. Magnetotransport measurements point to the Ba${}_2$FeMoO${}_6$ grains retaining the high spin polarization of a half-metal up to $T_C$, while the grain boundaries greatly reduce the spin polarization of the intergrain electrical current due to spin-flip scattering. Our results show that a strong spin polarization of the electronic charge carriers is present even in Ba${}_2$FeMoO${}_6$ films that do not show the ideal bulk magnetic character.

10 pages (single column), 6 figures